1. Field of the Invention
The present invention relates generally to accumulator devices for air-conditioning systems. More particularly the present invention relates to an accumulator dehydrator for use in an automobile's air-conditioning system and the attachment of a deflector, or baffle, within the accumulator housing, to an outlet tube.
2. Description of the Prior Art
One type of vehicle air-conditioning system includes a compressor, a condenser, an evaporator and an accumulator dehydrator. Accumulator dehydrators (or accumulators) for vehicle air conditioning systems function to allow liquid refrigerant to change to a gaseous refrigerant fluid or vapor prior to being sent to the compressor. The accumulator receives liquid and gaseous refrigerant fluid from the evaporator through an inlet tube and ensures only gaseous or vaporous refrigerant fluid is sent to the compressor by means of an outlet tube.
Most accumulator assemblies incorporate a baffle plate or deflector situated within the accumulator can, near the top of the accumulator, to prevent the liquid refrigerant entering the accumulator from entering the exit tube. The liquid refrigerant fluid flows onto the deflector and is dispersed down the sides of the accumulator housing. An outlet tube, or "J" tube, passes through the deflector and through the top of the accumulator to return the gaseous refrigerant fluid to the compressor.
One example of the prior art type deflector is U.S. Pat. No. 4,474,035, awarded to Arnin et al., the specification of which is incorporated herein by reference. Prior art accumulator deflectors are generally assembled to the inside of the accumulator housing by means of a press or interference fit. The deflector usually has protrusions equally spaced apart from each other and contacting the inside diameter of the accumulator can resulting in an interference fit which is intended to hold the deflector in place. However, these types of deflectors are difficult to assemble and are not compatible with all types of material, in particular, aluminum.
U.S. Pat. No. 4,768,355, awarded to Bretban et al., discloses a cartridge positioned within the accumulator can for processing the flow of refrigerant fluid. The cartridge casing embodies retention and locating structures extending from the casing. The outlet tube is connected to the cartridge by the combination of a coupling tube and an O-ring seal. The combination coupling tube and O-ring seal comprise a port for sealingly receiving the outlet tube and means for connecting the refrigerant processing cartridge with the outlet tube. The cartridge itself is retained within the accumulator housing by means of retention and locating tabs which contact embossments on the inner surface of the accumulator housing.
U.S. Pat. No. 5,184,479, awarded to Koberstein et al., discloses an accumulator with an outlet tube within the housing which exits at the bottom of the housing, and an outlet tube shield, or deflector, mounted at the top of the housing to temporarily impede the flow of refrigerant passing between the inlet tube and the outlet tube. The outlet tube shield is welded or brazed to the inlet tube between the housing and the free end of die outlet tube.
These known accumulator assemblies are usually made of metal, such as steel. When applying the interference fit design of prior art deflectors to an accumulator made of aluminum, difficulties result from tolerance stack-up, hardness, and coefficients of friction. Because aluminum has a lower elasticity than steel, it is not possible to apply the press fit design for a steel accumulator deflector directly to an aluminum application. In addition, aluminum to aluminum contact tends to gall and fuse together when an interference fit is attempted.
A solution may lie in tack welding each of the protrusions on the accumulator deflector to the inside of the accumulator housing. Bead locking or other mechanical operations may be used as potential solutions as well. However, these additional assembly and process steps add unnecessary complexity and cost to the accumulator. The mechanical operations also introduce the potential for failure.
U.S. Pat. No. 4,111,005, awarded to Livesay, discloses a press-on baffle that is made entirely of plastic. The baffle is secured by three, spaced apart upwardly tapered webs each of which supports a vertically extending arcuate rib portion providing a press fit with the standpipe or outlet tube.
The problem with this approach is the inflexibility in the design of the plastic baffle. The baffle must be designed around a specific standpipe diameter to successfully retain the standpipe. The costs associated with a large die for intricate plastic molding are very high. In addition, the plastic baffle surface is not as durable as aluminum or steel in an area which must withstand refrigerant fluid pulsing in from the compressor at relatively high pressures and cycle rates.
Based upon the above, it should be appreciated that there is still a need to provide an accumulator having a deflector which is inexpensive, easy to manufacture and install, and will withstand the relatively harsh environment inside an accumulator dehydrator.
It is an object of the present invention to improve the design of an accumulator deflector assembly and eliminate problems associated with using aluminum such as blowby of refrigerant fluid past an all-aluminum deflector without adding unnecessary cost or processing steps to the accumulator and its assembly process.